FIG. 1 illustrates wind turbine 1, comprising a wind turbine tower 2 on which a wind turbine nacelle 3 is mounted. A wind turbine rotor 4 comprising at least one wind turbine blade 5 is mounted on a hub 6. The hub 6 is connected to the nacelle 3 through a low speed shaft (not shown) extending from the nacelle front. The wind turbine illustrated in FIG. 1 may be a small model intended for domestic or light utility usage, or may be a large model, such as those that are suitable for use in large scale electricity generation on a wind farm, for example. In the latter case, the diameter of the rotor could be as large as 100 metres or more.
Wind turbine blades are typically made by forming two blade halves or shells, which are then bonded together to form the complete blade. Failure of the bond between the two shells, often called blade delamination, is a serious problem, as it most often occurs after the blade has been installed on a turbine.
The bonding process used to bond the two shells is critical in minimising the likelihood of delamination occurring and in increasing the useful lifetime of the turbine blade. Typically, the bonding of the two shells is performed by applying a bonding resin to one or both of the shells, pressing the shells together, and then curing the bonding resin in an oven. The temperature of the bonding resin during the curing process is critical in achieving good bond strength.
Typically, the blade is placed in an oven, and the oven temperature and curing time is controlled based on empirical data obtained from the manufacture of previous blades. However, no two blades are ever identical, nor is the performance of the oven used necessarily identical each time that it is used. We have appreciated that there is a need to provide a system and method for more accurate control of the bonding process for blade shells during wind turbine blade manufacture.